That's not true. GMail was always JS heavy and run fine back in IE 6 and Firebird 0.7 (now Firefox) in 2004/05.
Where as the Java 1.4 consumed too much memory and every now and then a lot of CPU cycles for its garbage collection cycle. 512MB RAM memory was the minimum for Java VM to execute a single Java app and consuming almost all memory resources.
Where as the Java 1.4 consumed too much memory and every now and then a lot of CPU cycles for its garbage collection cycle. 512MB RAM memory was the minimum for Java VM to execute a single Java app and consuming almost all memory resources.